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Thread: 600 or 650 tvl camera

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    Default 600 or 650 tvl camera



    I currently have one Miracleon MVV6804 (600tvl, for outdoors). I am looking at getting an second camera . One of their higher spec cameras is 650 tvl.

    Based on the extra 50 tvl lines would it be worth the money? Is there really that much more quality in the images recorded?



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    Super Moderator mtv's Avatar
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    The difference between 600 and 650 lines isn't that great.

    Resolution depends on several factors apart from the TVL, the most important component is the lens, both in optical quality and aperture.

    The way the camera handles light is also critical, smear, contrast, noise etc.

    If the 650 lines camera costs a lot more but it's only the TVL that's higher, with no other optical/noise improvements compared to the 600 lines camera, I'd go with the 600 lines camera.

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    Quote Originally Posted by mtv View Post
    The difference between 600 and 650 lines isn't that great.

    Resolution depends on several factors apart from the TVL, the most important component is the lens, both in optical quality and aperture.

    The way the camera handles light is also critical, smear, contrast, noise etc.

    If the 650 lines camera costs a lot more but it's only the TVL that's higher, with no other optical/noise improvements compared to the 600 lines camera, I'd go with the 600 lines camera.
    Thanks can you suggest a camera for outdoor Use for around $300?

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    Unless you are recording with a 960H Recorder then I think anything ober 600tvl is a waste of time... Also the rule of thumb is the high the tvl / Megapixel the worse the camera in low light.

    Also you start looking for DOT MATRIX IR as they have a great IR Flood..

    Thanks Jamie

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    The PAL standard allows for display resolution of 720x576. What happens to the other lines? Unless you're talking HD CCTV or IP CCTV, the additional information is wasted. Analogue DVRs record at a max resolution of either D1 (720x576) or 4CIF (704x576) so it's of no use to you there either.

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    Thanks for all the replies much appreciated.

    My current camera has built ir however a bit more would be good, what extra ir illumination should I use? Invisible? Visible? Where should I position it, above or below the camera?

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    Senior Member intelliGEORGE's Avatar
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    Default In a nutshell...

    Whilst the big numbers look good in the glossy print and end-users think bigger is better, 540(H)TVL is the practical limit in analog CCTV systems.

    The number "540" is not a magical number, CCTV manufacturers didn't sit around a camp fire and vote unanimously for 540TVL. This number is the result of an analog signal passing through a low-pass filter found in the composite input circuitry (BNC or RCA) of monitors and DVR's.

    Analog signals pass through a low-pass filter to prevent any cross talk between the color sub carrier and the luminance information before they are converted to digital signals. It is this conversion process that limits the resolution on any composite signal to 540TVL.

    The conversion process samples analog video signals and converts them to digital based on the Rec. 601 (CCIR 601) industry standard (720 luminance samples per horizontal line).

    Therefore, 720 x 0.75 (limitation to 3/4 of the width due to aspect ratio) = 540HTVL.

    Then there is (V)TVL (Vertical TV Lines), which are not quoted in marketing paraphernalia and for very good reason; Total Resolution.

    The total resolution of an image is essentially HTVL x VTVL and up until megapixel cameras, VTVL's have not been openly promoted as they are limited by the technology used in image capture. For example, some CCD sensors use line-pair summation for interlaced video capture. This process also acts like a low-pass filter to overcome image flicker, however it decreases "effective" vertical resolution by 25%.

    Therefore, a 480 line CCD has an effective vertical resolution of 360 lines making the 'Total Resolution' reduced by 25% and doesn't look too good on glossy brochures.

    Progressive scan CCD's (most commonly found in IP/Megapixel cameras) on the other hand do not suffer from this, enabling them to utilise all 480 lines.

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    Quote Originally Posted by intelliGEORGE View Post
    Whilst the big numbers look good in the glossy print and end-users think bigger is better, 540(H)TVL is the practical limit in analog CCTV systems.

    The number "540" is not a magical number, CCTV manufacturers didn't sit around a camp fire and vote unanimously for 540TVL. This number is the result of an analog signal passing through a low-pass filter found in the composite input circuitry (BNC or RCA) of monitors and DVR's.

    Analog signals pass through a low-pass filter to prevent any cross talk between the color sub carrier and the luminance information before they are converted to digital signals. It is this conversion process that limits the resolution on any composite signal to 540TVL.

    The conversion process samples analog video signals and converts them to digital based on the Rec. 601 (CCIR 601) industry standard (720 luminance samples per horizontal line).

    Therefore, 720 x 0.75 (limitation to 3/4 of the width due to aspect ratio) = 540HTVL.

    Then there is (V)TVL (Vertical TV Lines), which are not quoted in marketing paraphernalia and for very good reason; Total Resolution.

    The total resolution of an image is essentially HTVL x VTVL and up until megapixel cameras, VTVL's have not been openly promoted as they are limited by the technology used in image capture. For example, some CCD sensors use line-pair summation for interlaced video capture. This process also acts like a low-pass filter to overcome image flicker, however it decreases "effective" vertical resolution by 25%.

    Therefore, a 480 line CCD has an effective vertical resolution of 360 lines making the 'Total Resolution' reduced by 25% and doesn't look too good on glossy brochures.

    Progressive scan CCD's (most commonly found in IP/Megapixel cameras) on the other hand do not suffer from this, enabling them to utilise all 480 lines.
    Ditto.
    Buy my camera, it has 700tvl and will work a treat on your pre 2005 recorder.

    650tvl cams look nice on a HD monitor...

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